We use rrweb as a DOM-recorder in our extension, and it does come with some limitations. Taken from our docs:

- DOM recording has the fundamental trait that nothing outside the DOM can be recorded. This latter limitation means that only content on the specific page is recorded: Data in popup dialogs or other tabs is not recorded, neither is anything outside the HTML document like native MacOS/Windows menus shown for native HTML selects.

- On top of that, some embeddable elements like <canvas> are not recorded (e.g. Google Maps, Figma).

- When playing back DOM recordings, there can be visual glitches, like duplicate elements being shown. Even when there’s no obvious glitches, a DOM recording is unlikely to look exactly like the page as experienced by the session reported.

- Security configuration like CORS on the recorded site’s hosting, and Bird’s own CSP policy can prevent the loading and rendering of embedded elements, like the original page’s font.

- Because DOM recordings don’t include all information (e.g. image files are only linked to), DOM recordings can drift apart from the time of the recording in fidelity over time, if the content of the asset behind the URL changes, or even degrade, or when the assets are no longer accessible at all at the URL.

Having said that, we found that rrweb is quite reliable on most situations and works well for most of our users.

Replay.io is a different beast altogether. They implement their tooling on their own browser (Chromium-based), so they have access to much more precise data than a JS-library like rrweb does. More info here: https://blog.replay.io/how-replay-works

> - On top of that, some embeddable elements like <canvas> are not recorded (e.g. Google Maps, Figma).

rrweb is capable of canvas recording. We use it at sentry but there are inherent challenges with canvas you have to be aware of. Most importantly we're very careful about PII handling and if you have canvases you will sooner or later capture stuff you do not want to have on there unless you are very careful yourself.

Maintainer of rrweb here. I used replay.io for debugging sometimes, it’s really quite useful. It is however a standalone browser and it works by intercepting quite low level browser calls which is only possible to do with a forked version of a browser. So it’s great for debugging if you know what you’d like to reproduce or deep-dive into. rrweb is more versatile as it can run in any browser and you could use it for analytics, live streaming for support, or recording tutorial videos like we do at https://recordonce.com

Believe Sentry use it in their session replay product

We do and we're not alone. I really like rrweb and I think it's the strongest library in the space.